As the dissemination of a 3 dimensional television (3DTV) is raging, a transmission of a 3D image content performed by a digital broadcasting as well as the dissemination of the 3D image content performed by a storing media is vitalized.
In general, a 3 dimensional image provides a 3D effect using a principle of stereo vision of two eyes. Since a human feels perspective via parallax of two eyes, in other word, binocular parallax due to a space between two eyes apart from each other about 65 mm, the 3D image may provide the 3D effect and the perspective in a manner of providing an image, which makes a left eye and a right eye see a related plane image, respectively.
The 3D image display method includes a stereoscopic technique, a volumetric technique, a holographic technique, and the like. In case of the stereoscopic technique, it provides a left view image supposed to be watched by a left eye and a right view image supposed to be watched by a right eye. The stereoscopic technique enables to recognize a 3D image effect in a manner of making the left eye and the right eye watch the left view image and the right view image respectively using a polarized glasses or a display device itself.
In case of a stereoscopic 3D image content, if two similar images having viewpoints different from each other are transmitted, the stereoscopic technique uses a technique that a receiver displays a 3D image using the two images. In case that the 3D image is displayed by the receiver, the 3D image is provided in a manner that the binocular disparity occurs due to a disparity between a left view image and a right view image.
A digital broadcasting may be able to include a 2D image program and a 3D image program. For instance, after broadcasting a movie made by a 3D image, a following advertising image may correspond to a 2D image. In this case, a broadcasting receiver should precisely catch a timing point of a conversion from the 3D image to the 2D image. If the timing point is not clear, it is unable to provide a normal image program to a user. In particular, if the receiver is still configured to display the 3D image program but a received program corresponds to a 2D, either a left view image or a right view image no longer exists and then an abnormal screen is displayed.
And, in case that the receiver supports a full resolution, the receiver may be able to operate in a frame-compatible compatible mode or a 2D service compatible mode according to a broadcast signal transmitted by a broadcasting station. In this case, the receiver should precisely catch a timing point of conversion between modes as well. Otherwise, it is unable to provide a normal screen to the user since a received signal and a mode of the receiver are not matched with each other.